WASHINGTON (CNN) --Howard Dean launched a TV ad in Iowa on Monday blasting Democratic foe Dick Gephardt for backing President Bush on the war in Iraq.

The two men are the top contenders in Iowa's presidential caucuses, to be held January 19.

Gephardt, a veteran congressman and popular son from neighboring Missouri, has inched ahead of the former Vermont governor in recent polls after ramping up his criticism of Dean, the leading antiwar candidate.

The ad shows Gephardt in the White House Rose Garden last year with the president announcing details of the congressional resolution authorizing Bush to go to war against Iraq. It is the first ad of the 2004 race to mention another Democratic presidential candidate by name.

In the ad, a female voice-over says: "October 2002 -- Dick Gephardt agrees to co-author the Iraq war resolution, giving George Bush the authority to go to war. A week later, with Gephardt's support, it passes Congress."

The commercial goes on to note that Gephardt supported Bush's recent $87 billion spending request for Iraq and Afghanistan. Dean tells viewers that he opposed both the war resolution and the spending bill, adding, "our party and our country need new leadership."

Gephardt campaign manager Steve Murphy issued a statement noting that Dean said in a TV debate in September "we have no choice" but to support the president's $87 billion request.

In that debate, Dean also said the $87 billion appropriation should be paid for by repealing the tax cuts Bush has signed into law.

Murphy called the ad "a political calculation," and "not a leadership decision."

Sarah Leonard, Dean's Iowa spokeswoman, said the ad is not negative and does not contain a single word critical of Gephardt.

"It's very factual," Leonard said. "It lays out the facts. If the Gephardt campaign doesn't like the facts, then they have a problem with their record."

Bill Burton, Gephardt's Iowa spokesman, said Dean's commercial was the first negative ad ever to run ahead of the Iowa caucuses.

A Dean spokesman said the ad would run through November 26 and that it cost $250,000.

At the annual fund-raising dinner of the party in Des Moines, Iowa, on Saturday, Dean complained of "gang tackling" after he drew the fire of five of his Democratic rivals, including Gephardt. For his part, Sen. John Edwards warned Democrats against the dangers of becoming a "party of anger," a trait often associated with Dean. (Full story)

Wesley Clark, a retired general who is also running for the Democratic presidential nomination on an antiwar platform, is skipping the Iowa caucuses, pinning his hopes instead on a fair showing in the New Hampshire primary in January and victories in Southern states in February. (Full story)